|Time to change timing chain
Question : MY 1991 Mercedes Benz 260E has covered 180,000km. There is no mention
in the owners' manual on the renewal
of the timing chain so could you advise
on when this is necessary?
Also, could you please elaborate on
the differences between "single" and
"twin" timing chains.
THE timing chain is a more robust
method of power transfer than the
toothed rubber belt. The metal chain has
an almost infinite operating life but is a
little noisier in operation and is more
expensive to manufacture compared to
the rubber belt.
Renewing a timing chain usually
involves more work than replacing a
toothed rubber timing belt.
The chain itself usually does not fail but problems are caused by other
factors. The most common is lubrication failure caused
by blockage of the channels sup-
plying oil to the chain tensioner. A lack of lubrication results in wear on the
surface of the tensioner along which the chain
A worn chain is characterized
by a rattling noise, usually on gentle
acceleration. If this happens, renewal of
both chain and tensioner is the only remedy. In some cases, the chain driving
sprocket(s) require replacement as well.
Single or simplex timing chains have a
single row of rollers whereas the double or
duplex chains have two rows of rollers.
Duplex chains are inherently stronger
than simplex ones.